Unlimited history in tmux

Do NOT set it to something like:

set -g history-limit 999999999

This will pre-allocate that many lines (and hence memory) for all windows, which is going to cripple your machine the more history is stored over time.

Set it to something large, by all means but not THIS large.

From what I can tell, you can only do this in a "practical" fashion, by setting the history to an absurdly large number. e.g.:

set -g history-limit 999999999

UPDATE: see the other answer as to why you don't want to use a number this high. Something more reasonable (less 9's) would be best.

UPDATE again: perhaps pre-allocation doesn't occur. @Volker Siegel's comment on the other answer indicates that setting the value does not cause memory allocation.